There are many types of wind-propelled toys and large scale recreational vehicles that are land vehicles. Land vehicles of this type include a sail for capturing the wind and wheels to support a vehicle frame which carries the sail. Typically these vehicles are of tricycle-type construction with two widely spaced apart rear wheels mounted on a rear axle and a single steerable front wheel. It is further known to have toy vehicles of this type radio-controlled. A servo/receiver mounted on the vehicle receives radio frequency signals from a controller. A receiver with servomotors in turn regulates a steering mechanism for the front wheel and drive means to orient the sail with respect to the vehicle frame.
A problem with vehicles of this type is their tendency to tip over uncontrollably in a strong wind. Various attempts to mitigate the tip-over problem have included flexible outrigger wheels, special weight distribution, and positioning the center of gravity of the vehicle with respect to the wheels. Unfortunately these attempts to provide a stable vehicle which will operate at high speed without tipping over have not been completely successful. Furthermore, string boom controllers which have been used to replicate sailboat-type maneuvering have a problem because the string becomes loose when the boom swings from one side to another and the string length control mechanism, usually a spool or winch-type drum, can cause the string to tangle thus disabling the boom control system.
Boom control and steering control are key to stable high speed operation of toy vehicles of this type. Pertinent U.S. Patent prior art of which the applicant is aware includes U.S. Pat. No. 4,886,478 issued to Jones and U.S. Pat. No. 6,579,146 issued to Ganz. The patent to Jones describes a boom having its movement restricted by a loose string and a front wheel steering mechanism comprising a pair of cables which extend from a rearwardly-mounted servomotor to the forward steered wheel. The patent to Ganz discloses an unguided string-controlled boom and a wire extending to a control arm on the front wheel from the servomotor for steering the front wheel. Neither of these systems for steering and boom control provide the degree and accuracy for stable high speed operation of a wind-propelled toy vehicle. Also, neither reference discloses any means for preventing the vehicle from tipping over.
There is therefore a need for a wind-propelled toy vehicle of the radio-controlled type which can operate controllably and travel at high speeds without tipping over. The vehicle should also be inexpensive to manufacture and be of rugged construction with a high degree of operational reliability.